I historically compare changes in institutional frameworks creating academic positions linked to temporary employment by analyzing university employment statistics in Chile, Colombia, Germany, and the USA. I find that temporary aca demic positions were institutionalized through the creation of previously inexist ent academic categories called a contrata in Chile, de cátedra in Colombia, "junior professor" without tenure in Germany and "postdoc" in the USA; used in higher education and employment laws since 1989, 1992, 2002, and 1974, respec tively. Under institutional frameworks demanding the maximization of students and research, universities have increasingly contracted academics through tem porary contracts under rationales that differ between regions. In Colombia and Chile, public university leaders and owners of private universities contract such teaching positions to expand student numbers through lowering costs. In Germany and the USA, employment insecurity is mostly driven by temporary scientific positions under a main rationale of scientific expansion. The share of temporary positions has increased exponentially in Colombia and Germany in recent dec ades, whereas in the USA there has only been an increase since 2012. Moreover, in Chile, the share of permanent positions has decreased since 2012. The common trend is one of isomorphism of vertical academic structures sharing a pyramidal form, with a wide base of academics working under conditions of contractual insecurity. Such trends follow a rationale for maximization of student numbers as